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Ivo Henrique Alexandrino Carapinha,1 Giancarlo De la Torre Canales,1– 3 Rodrigo Lorenzi Poluha,4 Mariana Barbosa Câmara-Souza,3 Nikolaos Christidis,2 Malin Ernberg,2 Andre Mariz de Almeida,1 Ana Cristina Garcia de Matos Manso1 1Egas Moniz Center for Interdisciplinary Research (CiiEM); Egas Moniz School of Health & Science, Almada, Portugal; 2Division of Oral Diagnostics and Rehabilitation, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden; 3Department of Dentistry, Ingá University Center, Uningá, Paraná, Brazil; 4Department of Dentistry, State University of Maringá, Paraná, BrazilCorrespondence: Giancarlo De la Torre Canales, Tel +351 913025948, Email gcanales@egasmoniz.edu.ptAbstract: The literature on Temporomandibular Disorders (TMD) incidence commonly reports sociodemographic factors such as gender and age. However, the role and prevalence of other sociodemographic factors in TMD are not well defined. Therefore, this scoping review aimed to report the prevalence of sociodemographic factors in TMD patients. A systematic search was conducted in the PubMed and Web of Science databases to identify clinical trials in adult populations, using the Research Diagnostic Criteria for TMD (RDC/TMD) or the Diagnostic Criteria for TMD (DC/TMD) and reporting sociodemographic data in TMD patients. Twenty-seven studies meeting the criteria were included in this review. The most commonly reported sociodemographic factors assessed in the included studies were age, race, education, job, income, and marital status. TMD prevalence was observed to be higher among younger and divorced individuals among the included studies. However, conflicting results were found for education level, and employment was not considered a risk factor for TMD. Although this review has methodological limitations, it suggests an association between TMD incidence and certain sociodemographic factors; nevertheless, further studies are needed to establish this relationship more

Objective: Temporomandibular disorders (TMD) are common. They affect abilities for carrying out daily tasks and influence different psychological aspects. In addition to standard treatment, psychological treatments have been suggested. The aim was to investigate the effects of psychological treatments on patients with painful TMD in a short- and long-term perspective. Materials and Methods: An electronic search was conducted in the databases MEDLINE, CINAHL, EMBASE, the Cochrane Central Registry of Controlled Trials (CENTRAL), and Web of Science for randomized clinical trials (RCTs) reporting psychological interventions for TMD. Registered beforehand in PROSPERO (CRD42022320106). In total, 18 RCTs were included; six RCTs that could be used in the meta-analysis, and all 18 RCTs were used in the narrative synthesis. Risk of bias was assessed by the Cochrane's tool for assessing risk of bias and certainty of evidence by GRADE. Results: The narrative synthesis indicates that psychological treatment options seem equivalent to standard treatment for painful TMD. The meta-analysis showed that a combination of psychological treatment and standard treatment and manual treatment (very low-quality evidence) are significantly better in pain reduction than just counselling and standard treatments of TMD. Conclusion:This study indicates that psychological treatments seem to reduce pain intensity in individuals with painful TMD, and that the effect seems to be equally good as standard treatment. However, a combination of psychological treatments and standard treatments seems to have an even better effect. This indicates that psychological treatments are promising as an additional treatment approach for painful TMDs.

Fibromyalgia (FM) is a complex disorder and a clinical challenge to diagnose and treat. Microdialysis is a valuable tool that has been used to investigate the interstitial proteins and metabolites of muscle in patients with fibromyalgia. The implantation of the catheter in the muscle causes acute tissue trauma and nociception. The aim of this study was to investigate acute proteome changes in the vastus lateralis muscle in women fibromyalgia patients (FM) and healthy subjects (CON). A further aim was to study if a 15-week resistance exercise program in FM had any influence on how chronic painful muscle responds to acute nociception. Twenty-six women patients with FM and twenty-eight CON were included in this study. A microdialysis catheter (100 kilo Dalton cut off, membrane 30 mm) was inserted in the vastus lateralis muscle, and samples were collected every 20 min. Subjects rated pain before catheter insertion, directly after, and every 20 min of sample collection. Dialysate samples from time points 0-120 were pooled and considered trauma samples due to the catheter insertion. The samples were analyzed with nano-liquid chromatography-tandem mass spectrometry (nLC-MS/MS). Advanced multivariate data analysis was used to investigate protein profile changes between the groups. Multivariate data analysis showed significant (CV-ANOVA p = 0.036) discrimination between FM and CON based on changes in 26 proteins. After the 15-week exercise intervention, the expression levels of the 15 proteins involved in muscle contraction, response to stimulus, stress, and immune system were increased to the same expression levels as in CON. In conclusion, this study shows that microdialysis, in combination with proteomics, can provide new insights into the interstitial proteome in the muscle of FM. In response to acute nociception, exercise may alter the innate reactivity in FM. Exercise may also modulate peripheral muscle proteins related to muscle contraction, stress, and immune respons

Background Higher education tends to focus on academic writing only, instead of emphasizing that professional texts are also used as a basis for communication in contexts with a variety of participators. When it comes to clinical notes, research is scarce and focused on technology and informatics. Therefore, the aim was to explore dental students’ clinical notes, and specifically which aspects of the clinical notes characterizes clinical notes that are not sufficient enough for professional purposes. Methods The object of analysis was the student’s written completion of a teacher constructed protocol regarding oral mucosa, the dental apparatus including pathology on tooth level, oral hygiene, and a validated international clinical examination protocol of the temporomandibular region. The study was framed within the New Literacy Studies approach, and the clinical notes were analyzed using thematic analysis. Results Within the clinical notes three themes were identified; a) familiar content; b) familiar content in new context; and c) new content. The forms of notes could refer to either categorizational clinical notes or descriptive clinical notes. Most students were able to write acceptable clinical notes when the content was familiar, but as soon as the familiar content was in a new context the students had difficulties to write acceptable notes. When it comes to descriptive notes students suffered difficulties to write acceptable notes both when it came to familiar content, or familiar content in a new context. Conclusions Taken together, the results indicate that students have difficulties writing acceptable notes when they are novices to the content or context, making their notes either insufficient, too short or even wrong for professional purposes. With this in mind, this study suggests that there is a need to strengthen the demands on sufficient professional quality in clinical notes and focus on clinical notes already in the early stages of the different medi, Skrivande inom akademin och tre professioner - vad, hur och varför skriver studenter?

Monitoring the immune system's regulation and signaling using saliva could be of interest for clinicians and researchers. Saliva, a biofluid with close exchange with serum, is influenced by circadian variance and oral factors such as masticatory function. This study investigated the detectability and concentration of cytokines and chemokines in saliva in children with juvenile idiopathic arthritis (JIA) as well as saliva flow and the influence of orofacial pain on saliva flow. Of the 60 participants (7-14 years old) enrolled, 30 had a diagnosis of JIA and active disease, and 30 were sex- and age-matched healthy controls. Demographic data and three validated questions regarding presence of orofacial pain and dysfunction were recorded. Stimulated whole saliva was collected and analyzed using a customized R&D bead-based immunoassay with 21 targeted biomarkers. Fourteen of these were detectable and showed similar levels in both children with JIA and controls: TNF-alpha, TNFRSF1B, MMP-2, MMP-3, IL-1alpha, IL-1beta, IL-6R alpha, IL-8, S100A8, CCL2, CCL3, IL-10, CCL11, and CXCL9. In addition, there was no difference in salivary flow rate between groups, but there was an association between orofacial pain and reduced saliva flow rate for both groups.Trial registration: ClinicalTrials.gov Protocol id: 2010/2089-31/2.

application/pdf, Environmental Research Letters. 2022, 17, P.054051

BACKGROUND: Although many children with juvenile idiopathic arthritis (JIA) develop arthritis and deformity of the temporomandibular joint (TMJ), many go undetected. OBJECTIVE: This study investigates whether findings from patient history and clinical examination using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) can be used to diagnose TMJ involvement. METHODS: As a part of the screening program, 59 consecutive JIA patients age 7-14 years underwent a clinical examination according to RDC/TMD including self-reported orofacial pain and pain related to jaw function, and cone beam computer tomography (CBCT). Data were obtained from the patient's medical charts. Patients were divided into two groups based on the presence or absence of TMJ deformities on CBCT. RESULTS: Self-reported TMJ symptoms before inclusion were reported by 52% of children with and 18% of children without TMJ deformities on CBCT (p = .020). On a group level, the maximum unassisted (mouth) opening (MUO) with and without pain was within the normal range, but children with TMJ deformities showed a significantly smaller MUO with pain (p = .035). A diagnosis of osteoarthritis and osteoarthrosis was more prevalent in children with TMJ deformities. CONCLUSION: Although there were few differences between children with and without radiographic TMJ deformities, self-reported previous TMJ symptoms and reduced MUO with pain could indicate the presence of TMJ involvement. However, radiographic examinations are needed to confirm TMJ involvement. Thus, this study indicates that the RDC/TMD protocol is a blunt tool when targeting TMJ involvement in JIA.

BACKGROUND: Academic reading and writing are seen as self-evident literacy competences in most contemporary higher educations, however, whether students also are introduced to professional literacy of relevance for dentistry during their education is a question. The purpose of this study is to analyze one of the Swedish dental programmes, with respect to its design, in relation to possible content of relevance for academic and professional literacy. Secondarily, to identify and analyze Swedish dental students' writing in an academic setting, i.e. what these students are expected to read and write, and how they write. METHODS: Data, for this ethnographically inspired case-study, was produced by observations and audio-recordings of lectures, copies of teachers' handouts and of volunteering students' notes, and a multiple-choice-test. Data-analysis was made in five steps, starting with macro-level data, i.e. curriculum and syllabuses, followed by the syllabuses for the two observed modules, the teacher-provided material, analysis of the students' notes, while in the fifth and final step, the results from the previous steps were compared, to find patterns of what students were expected to read and write, and what in the teacher-provided multimodal material that was emphasized in teachers' talk. RESULTS: This study showed that students were engaged in several types of literacy events, such as reading, finding and watching videos on their learning platform, writing, and following instructions. The study also showed that there is a recurrent academic content comprised of anatomy, physiology and pathology, while the professional content comprised of patient communication and anamnesis. Further, an integrated content was found and was initiated in teacher-constructed PowerPoints and by student-questions. Note-taking patterns varied between individual students, but the general pattern for this group of students were the use of complementary notes. This type of note-taking was

Background: The transition from upper secondary to higher education and from higher education to professional practice requires that students adapt to new literacy practices, academic and professional. However, there is a gap of knowledge regarding literacy practices in dental education. Therefore, the aim of this study was to identify what characterizes dental students’ notetaking and secondarily to determine what dental students express regarding their notetaking. Methods: To analyze students’ perspectives about the purposes of notetaking and to examine their written notes in depth, three volunteer students, out of the 24 students that voluntarily and anonymously handed in their notes, were interviewed. The three undergraduate dental students that participated in this material-based, semi-structured interview study, framed within a New Literacy Studies approach, were on their third year (6th semester). The focus of these material-based interviews was on each student’s notes. Questions prepared for semi-structured interviews were open-ended and allowed for individual follow-up questions related to the interviewee’s answer. To analyze the outcome of the interviews a thematic analysis was used. Results: From the material-based interviews eight themes that relate to what, how and for what purpose students write were discerned. These eight themes include professional vocabulary, core content as well as clinical examples that belong to what students read and write; multimodal accentuation as well as synthesis that belong to how students read and write; and mnemonic strategies, academic purposes, and professional purposes that belong to for what purpose students read and write. Conclusions: Findings from the interviews indicate that the digital development, offering a variety of available tools, has expanded the notion of notetaking. This study identified that dental students’ notetaking has changed during their education from initially being synchronous, to also include

As in other professional programmes within academia, part of the learning outcomes relates to content like anatomy and physiology, others relate to tools, and materials used for dental work and their properties – in everyday terminology the ‘theoretical’ aspects of dental work. Other learning outcomes relate to what a dentist does – the ‘practical’ (clinical) aspects of dental knowledge. Aspects of these are both understanding patient needs, hands-on-skills, being able to construct an anamnesis and explain oral conditions, treatment need and prognosis (Kurz, Draper & Silverman, 2016). Furthermore, as becoming a dentist requires attending an educational programme, reading and writing, i.e. literacy competences, are seen as self-evident aspects of contemporary education. While it seems obvious that it takes time to become a skilled dentist and a degree is the necessary beginning in this direction, it seems less obvious that it also takes time to become a skilled writer in academia. But future dentists not only examine or repair their clients’ teeth. Part of a dentist’s everyday work is also to document examinations and treatment, prescribe medicines, but also to communicate with other professionals about clients that may need complementary or specialist treatment. Transition from higher education to work requires that students can cope also with the literacy practices of the profession. Studies with this focus show that although a person may be a successful student, (s)he isn’t necessarily well acquainted with the kinds of literacy demands that (s)he will encounter when entering the world of work (Ask, 2017; Dias et al., 1999). Since the 1980s there has been a growing interest in literacy practices, that is, what people read and write in specific activities, how people are expected to read and write (what qualifies as an acceptable text) and for what purposes representatives for the activity read and write. Our focus is on literacy practices in professional high

AIMS: To investigate whether static jaw clenching can activate endogenous pain modulation and to compare the magnitude between healthy individuals and patients with temporomandibular disorder (TMD) myalgia. METHODS: Thirty-three healthy volunteers (17 women and 16 men) and 20 women with TMD myalgia participated. Exercise-induced hypoalgesia (EIH) was examined by recording pressure pain thresholds (PPTs) in the masseter (MA) and brachioradialis (BR) muscles during tooth clenching until exhaustion. Pain and fatigue were assessed before and after clenching, and pain amplification was examined by applying a painful mechanical pressure at the MA for 2 minutes while assessing pain every 30 seconds. Analyses of data included repeated measures analysis of variance. RESULTS: In the contracting MA, PPTs increased over time in all three groups (P < .001), while PPTs in the relaxed BR increased only in the men (P = .045). Pain intensity and fatigue in the MA increased after contraction in all groups (P < .003) and was higher in the women with TMD than in the healthy women (P < .001). Only the women with TMD showed pain amplification (P < .001). CONCLUSION: Tooth clenching until exhaustion could activate EIH locally; ie, the magnitude of EIH in the MA was similar in women with TMD myalgia and pain-free women, indicating no deficient EIH in women with TMD. However, only women with TMD showed pain amplification during application of continuous painful pressure.

The issue of this paper to scrutinise Swedish dental students’ writing in academic setting: what these students are expected to read and write, how they are expected to do this, and for what purposes they read and write. Dental education is one of several professional programmes in higher education. The national learning outcomes stated in the Higher Education Ordinance (SFS 1993:100- SFS 2017:284) point out for example the importance of knowledge of the scientific basis as well as of proven experience for dental work, the capability of making diagnoses aw well as treating various dental diseases and malformations, but also leadership and collaboration. Such learning outcomes obviously are abstract, as they coven a whole program of 300 ECTS, and are to be somewhat more concretized in syllabuses for the various courses that together form the programme. However, as in other professional programmes within academia, part of the learning outcomes relate to content like physiology and neurology, others relate to tools, and materials used for dental work and their properties – in everyday terminology the ‘theoretical’ aspects of dental work. Other learning outcomes relate to what a dentist does – the ‘practical’ (clinical) aspects of dental knowledge. Furthermore, as becoming a dentist requires attending an educational programme, reading and writing are seen as self-evident aspects of the education. While it seems obvious that it takes time to become a skilled dentist and a degree is the necessary beginning in this direction, it seems less obvious that it also takes time to become a skilled writer in academia – where the meaning of being a skilled writer varies between disciplines (Bazerman, 1995; Blåsjö, 2004; Hjalmarsson et al. 2017; Lea & Street 1998; Airey 2011). Being a student in any higher education assumes participating in an activity that to a large extent is literacy based. To have the literacy competences and strategies needed for educational activities are

BACKGROUND: This study aimed at investigating the effect of a resistance exercise intervention on the interstitial muscle levels of pro-inflammatory cytokines in fibromyalgia (FMS) and healthy controls (CON). METHODS: Twenty-four female patients with FMS (54 ± 8 years) and 27 female CON (54 ± 9 years) were subjected to intramuscular microdialysis of the most painful vastus lateralis muscle before and after 15 weeks of progressive resistance exercise twice per week. Baseline dialysates were sampled in the resting muscle 140 min after insertion of the microdialysis catheter. The participants then performed repetitive dynamic contractions (knee extension) for 20 min, followed by 60 min rest. Pain intensity was assessed with a 0-100 mm visual analogue scale (VAS), and fatigue was assessed with Borg's RPE throughout microdialysis. Dialysates were sampled every 20 min and analyzed with Luminex for interleukin (IL)-1β, tumor necrosis factor (TNF) alpha, IL-6, and IL-8. RESULTS: At both sessions and for both groups the dynamic contractions increased pain (P < 0.012) and fatigue (P < 0.001). The levels of TNF were lower in the FMS group than the CON group at both sessions (P < 0.05), but none of the other cytokines differed between the groups. IL-6 and IL-8 increased after the dynamic contractions in both groups (P < 0.010), while TNF increased only in CON (P < 0.05) and IL-1β did not change. Overall pain intensity was reduced after the 15 weeks of resistance exercise in FMS (P < 0.05), but there was no changes in fatigue or cytokine levels. CONCLUSION: Progressive resistance exercise for 15 weeks did not affect the interstitial levels of IL-1β, TNF, IL-6, and IL-8 in the vastus lateralis muscle of FMS patients or CON. TRIAL REGISTRATION: Clinicaltrials.gov NCT01226784 , registered 21 October 2010.

A growing field of research aims to characterise the contribution of anthropogenic emissions to the likelihood of extreme weather and climate events. These analyses can be sensitive to the shapes of the tails of simulated distributions. If tails are found to be unrealistically short or long, the anthropogenic signal emerges more or less clearly, respectively, from the noise of possible weather. Here we compare the chance of daily land-surface precipitation and near-surface temperature extremes generated by three Atmospheric Global Climate Models typically used for event attribution, with distributions from six reanalysis products. The likelihoods of extremes are compared for area-averages over grid cell and regional sized spatial domains. Results suggest a bias favouring overly strong attribution estimates for hot and cold events over many regions of Africa and Australia, and a bias favouring overly weak attribution estimates over regions of North America and Asia. For rainfall, results are more sensitive to geographic location. Although the three models show similar results over many regions, they do disagree over others. Equally, results highlight the discrepancy amongst reanalyses products. This emphasises the importance of using multiple reanalysis and/or observation products, as well as multiple models in event attribution studies.

BACKGROUND: Fibromyalgia syndrome (FMS) is associated with central alterations, but controversies exist regarding the presence and role of peripheral factors. Microdialysis (MD) can be used in vivo to study muscle alterations in FMS. Furthermore for chronic pain conditions such as FMS, the mechanisms for the positive effects of exercise are unclear. This study investigates the interstitial concentrations of algesics and metabolites in the vastus lateralis muscle of 29 women with FMS and 28 healthy women before and after an exercise intervention. METHODS: All the participants went through a clinical examination and completed a questionnaire. In addition, their pressure pain thresholds (PPTs) in their upper and lower extremities were determined. For both groups, MD was conducted in the vastus lateralis muscle before and after a 15-week exercise intervention of mainly resistance training of the lower limbs. Muscle blood flow and interstitial muscle concentrations of lactate, pyruvate, glutamate, glucose, and glycerol were determined. RESULTS: FMS was associated with significantly increased interstitial concentrations of glutamate, pyruvate, and lactate. After the exercise intervention, the FMS group exhibited significant decreases in pain intensity and in mean interstitial concentrations of glutamate, pyruvate, and glucose. The decrease in pain intensity in FMS correlated significantly with the decreases in pyruvate and glucose. In addition, the FMS group increased their strength and endurance. CONCLUSION: This study supports the suggestion that peripheral metabolic and algesic muscle alterations are present in FMS patients and that these alterations contribute to pain. After an exercise intervention, alterations normalized, pain intensity decreased (but not abolished), and strength and endurance improved, all findings that suggest the effects of exercise are partially peripheral.

OBJECTIVE: Fibromyalgia is associated with central hyperexcitability, but it is suggested that peripheral input is important to maintain central hyperexcitability. The primary aim was to investigate the levels of pro-inflammatory cytokines released in the vastus lateralis muscle during repetitive dynamic contractions of the quadriceps muscle in patients with fibromyalgia and healthy controls. Secondarily, to investigate if the levels of pro-inflammatory cytokines were correlated with pain or fatigue during these repetitive dynamic contractions. MATERIAL AND METHODS: 32 women with fibromyalgia and 32 healthy women (controls) participated in a 4 hour microdialysis session, to sample IL-1β, IL-6, IL-8, and TNF from the most painful point of the vastus lateralis muscle before, during and after 20 minutes of repeated dynamic contractions. Pain (visual analogue scale; 0-100) and fatigue Borg's Rating of Perceived Exertion Scale; 6-20) were assessed before and during the entire microdialysis session. RESULTS: The repetitive dynamic contractions increased pain in the patients with fibromyalgia (P < .001) and induced fatigue in both groups (P < .001). Perceived fatigue was significantly higher among patients with fibromyalgia than controls (P < .001). The levels of IL-1β did not change during contractions in either group. The levels of TNF did not change during contractions in patients with fibromyalgia, but increased in controls (P < .001) and were significantly higher compared to patients with fibromyalgia (P = .033). The levels of IL-6 and IL-8 increased in both groups alike during and after contractions (P's < .001). There were no correlations between pain or fatigue and cytokine levels after contractions. CONCLUSION: There were no differences between patients with fibromyalgia and controls in release of pro-inflammatory cytokines, and no correlations between levels of pro-inflammatory cytokines and pain or fatigue. Thus, this study indicates that IL-1β, I

BACKGROUND: Chronic myalgia is associated with higher muscle levels of certain algesic biomarkers. The aim of this study was to investigate if hypertonic saline-induced jaw myalgia also leads to release of such biomarkers and if there were any sex differences in this respect. METHODS: Healthy participants, 15 men and 15 aged-matched women (25.7 ± 4.3 years) participated. Intramuscular microdialysis into masseter muscles was performed to sample serotonin (5-HT), glutamate, lactate, pyruvate, glucose and glycerol. After 2 hours 0.2 mL hypertonic saline (58.5 mg/mL) was injected into the masseter on one side and 0.2 mL isotonic saline (9 mg/mL) into the contralateral masseter close to the microdialysis catheter. Microdialysis continued for 1 hour after the injections. Pressure pain thresholds (PPT) and pain were assessed before and after injections. RESULTS: The median (IQR) peak pain intensity (0-100 visual analogue scale) after hypertonic saline was 52.5 (38.0) and after isotonic saline 7.5 (24.0) (p < 0.05). 5-HT, glutamate and glycerol increased after hypertonic saline injection (p < 0.05). Lactate, pyruvate and glucose showed no change. PPT after microdialysis was reduced on both sides (p < 0.05) but without side differences. Pain after hypertonic saline injection correlated positively to 5-HT (p < 0.05) and negatively to glycerol (p < 0.05). CONCLUSIONS: 5-HT, glutamate and glycerol increased after a painful hypertonic saline injection into the masseter muscle, but without sex differences. Since increased levels of 5-HT and glutamate have been reported in chronic myalgia, this strengthens the validity of the pain model. Glycerol warrants further investigations.

The main aim of this thesis was to gain a better understanding of the influence of serotonin on chronic craniofacial muscle pain. The thesis comprised a basic science part and a human experimental part. The aim for the basic science part was to investigate if the expression of 5-HT3 receptors in muscle tissue differ between myalgic and healthy muscles and if sex or muscle site influence this expression. The aim for the human experimental part was to investigate if the specific 5-HT3 antagonist granisetron influences pain variables in patients with chronic craniofacial myalgia and experimental pain induced by hypertonic saline, as well as the mechanical pain threshold of healthy muscles. A second aim was to investigate if any effect by granisetron was influenced by sex, muscle site or route of administration, i.e. local or systemic. In the basic science part, patients with chronic local myalgia of the masseter muscle and age- and sexmatched healthy controls were examined clinically according to the Research Diagnostic Criteria for Temporomandibular Disorders. Traditional biopsies were taken intra-orally with a 4-mm Bergström needle from the most painful part of the masseter muscle in patients, and from a standardized point in the healthy controls. In order to compare if there were any differences in receptor expression due to sex or between muscles a microbiopsy technique was used to obtain masseter muscle and tibialis anterior muscle biopsies in healthy age-matched men and women. The patients were found to have a significantly higher amount of co-expressed 5-HT3A receptors and NaV1.8 sodium channels in the connective tissue compared to their healthy controls. This novel finding makes it presumable that in myalgic muscles proliferation of nociceptive nerve fibers occurs in the connective tissue surrounding the myocytes. Further, in healthy subjects, the co-expression of 5-HT3A receptors and NaV1.8 sodium channels in the masseter muscle was higher in women than in men